In process automation technology, field devices are often applied, which serve for registering and/or influencing process variables. Examples of such field devices are fill level measuring devices, mass flow measuring devices, pressure- and temperature measuring devices, etc., which, as sensors, register the corresponding process variables, fill level, flow, pressure, and temperature.
Referred to, in principle, as field devices are all devices, which are applied near to the process and deliver, or process, process relevant information.
A large number of such field devices are produced and sold by the firm, Endress+Hauser.
With the help of radar measurement apparatuses based on FMCW (Frequency Modulated Continuous Wave) radar, the fill level in a container or tank can be measured exactly. In the case of radar measurement in a pipe, however, special effects occur, because the pipe acts as a hollow conductor for the radar waves. Radar waves propagate differently in hollow conductors.